The Gemstone Alexandrite

Alexandrite is the highly regarded color changing variety of Chrysoberyl.
The color of Alexandrite changes under different lighting conditions.
If viewed in daylight, its color is
greenish blue to
dark yellow-green. If viewed in incandescent or candle light, its
color is pink to red. Alexandrite is a very rare and highly valuable
gemstone, and until recently was extremely difficult to obtain due to
its rarity. However, new sources in Brazil and Tanzania have made this
gemstone available and more mainstream on the gemstone market.

Color	Blue, Red, Green, Yellow, Pink, Purple, Gray, Multicolored
Hardness	8.5
Refractive Index	1.744 - 1.755
SG	3.5 - 3.8
Double Refraction	.009
Luster	Vitreous
Mineral Class	Chrysoberyl exandrite was first discovered in Russia in the early 1800's. It was named in honor of Alexandar Nicholavich, who was later to become the Russian Czar Alexander II. Legend has it that the gemstone was discovered on the future Czar's birthday and named in his honor, though the factual nature of this is disputed. The unique color change habit of Alexandrite is caused by slight impurities of the element chromium. The most desirable colors of Alexandrite are those that show a clearly visible pure hue color change, such as a pure green/blue in daylight to a pure red in incandescent light. In addition to its color-changing habit, Alexandrite is a pleochroic gem, showing different color intensity when viewed at different angles. This factor must be taken into account when cutting Alexandrite gemstones. Alexandrite exhibiting chatoyancy does exist but is very rare, thus Alexandrite Cat's eye is rarely available.

The Gemstone Alexandrite

The Gemstone Alexandrite :: تعاليق

The Gemstone Alexandrite